Prey species composition of Burmese python diet

Christina Romagosa, Paul Andreadis, Ian Bartoszek, Michelle Collier, Carla Dove, Bryan Falk, Jill Josimovich, Diego Juárez-Sánchez, Kenney Krysko, Frank Mazzotti, James Nifong, Robert Reed, Michael Rochford, Brian Smith, Skip Snow, Eric Suarez, Dustin Welbourne, Laurie Wilkins, countless python capturers

UF/IFAS, UF FLMNH, Smithsonian Institution, Conservancy of Southwest Florida, Everglades National Park, USGS

Python diet samples: the numbers (2003 – 2018)

•Pythons captured opportunistically or on road/levee surveys

•Diet contents (stomach/gut) from ~1500 pythons

• Identified ~2000 prey items•Avg # of prey items per snake = 1.30 •F = 529, M = 725, Unknown = 283

0.00

0.20

0.40

0.60

0.80

1.00

0.45 - 0.99 M 1.0 - 2.0F 1.0 - 2.5

M 2.1 - 2.9F 2.6 - 2.9

3.0 - 3.9 4.0+

Pythons per size class (SVL m)Pr

opor

tion

Breeding adults

n = 181

n = 839

n = 394

n = 81 n = 23

Python diet composition

Birds At least 43 speciesPied-billed GrebeWood DuckGreen-winged TealBlue-winged TealNorthern PintailNorthern ShovelerDomestic GooseDomestic ChickenLimpkinAmerican CootCommon GallinulePurple Gallinule

Sora RailKing RailVirginia RailClapper RailGreat EgretGreat Blue HeronGreen HeronLittle Blue HeronSnowy EgretBlack-crowned Night HeronLeast BitternAmerican Bittern

White IbisRoseate SpoonbillWood StorkWilson's SnipeWhimbrelDouble-crested CormorantAnhingaFrigatebirdBlack VultureMourning DoveNorthern CardinalBobolink

Red-winged BlackbirdBoat-tailed GrackleMeadowlarkHouse WrenRuby-crowned KingletCommon YellowthroatRed-whiskered Bulbul

MammalsDomestic GoatWhite-tailed DeerFeral HogGray FoxFeral catBobcatRiver OtterRaccoonArmadillo

OpossumShort-tailed ShrewLeast ShrewEastern CottontailMarsh RabbitRound-tailed MuskratKey Largo WoodratMarsh Rice Rat

Cotton MouseHispid Cotton RatHouse MouseBlack RatFox SquirrelGray Squirrel

At least 23 species

ReptilesAlligatorGreen Iguana

0.00

0.20

0.40

0.60

0.80

1.00

0.45 - 0.99 M 1.0 - 2.0F 1.0 - 2.5

M 2.1 - 2.9F 2.6 - 2.9

3.0 - 3.9 4.0+

Alligator

Bird

SmallmammalMidsizemammalDeer

n = 181 n = 839 n = 394 n = 81 n = 23

Diet by python size class

SW Florida (115 pythons)

Northern EVER (293 pythons)

Southern EVER (234 pythons)

Eastern EVER(179 pythons)

Locations

MammalBirdReptile

Northern EVER

SWFL

Southern EVER

Aquatic Birds

Wading/Marsh Birds

Other Bird

Unkn Bird

Unkn Mammal

Deer

Mesomammal

Rabbit

Rodent

Alligator

Eastern EVER

Aquatic Birds

Wading/Marsh Birds

Other Bird

Unkn Bird

Other Mammal

Unkn Mammal

Deer

Mesomammal

Rabbit

Rodent

Alligator

Northern EVER

SWFL

Southern EVER

Aquatic Birds

Wading/Marsh Birds

Other Bird

Unkn Bird

Unkn Mammal

Deer

Mesomammal

Rabbit

Rodent

Alligator

Aquatic Birds

Wading/Marsh Birds

Other Bird

Unkn Bird

Other Mammal

Unkn Mammal

Deer

Mesomammal

Rabbit

Rodent

Alligator

Eastern EVER

Lower Everglades

Southwest Florida

Has diet changed over time?

• In some areas data don’t go back far enough

• Inconsistent sampling•Not enough representative

samples

1985

20182003

2009

Diet samples per time period and location

0

20

40

60

80

100

120

140

SWFL Northern EVER Eastern EVER Southern EVER

2003-20062007-20102011-20142015-2018

0

0.2

0.4

0.6

0.8

1

2004-2008 2013-2017 2004-2008 2013-2017

NorthernEVER SouthernEVER

Bird

Mammal

Reptile

Proportion of diet for pythons between SVL 2 – 4 m3

30

52

9

9

11

10

3

15

13

3

27

Has diet changed over time?

•MUST look at trends by location

•Needs:– Targeted sampling

–Specific locations–Size classes–Seasonal

?

Ecosystem level effects

?

Ecosystem level effects

?

Ecosystem level effects

?

Indirect effects ( — , +)

Ecosystem level effects

?

Indirect effects ( — , +)

Ecosystem level effects

?

??

Indirect effects ( — , +)

Ecosystem level effects

AcknowledgementsUSGS – Fort Collins Science Center and Everglades National Park

Everyone who has ever caught a python and brought it in

Identification of Divergent Nidoviruses in Free-Ranging

Invasive PythonsSteven Tillis, Melissa Miller, Jillian Josimovich, Natalie Claunch,

Ian Bartoszek, John Humphrey, Bryan Kluever, Robert Reed, Christina Romagosa, Jim Wellehan, Robert Ossiboff

What is Nidovirus?• Large viral group causing respiratory illness in many

animals• Causative agent of respiratory infection in captive

reptiles with large diversity of virus species found in pythons and boas

• Species of virus seen in wild population of shingleback skinks and Bellinger River snapping turtle

• Host range of each virus species still being investigated

How the Project Was Started

• USDA Gainesville Field Station BPNV outbreak (seen in captive snake colonies) in their Burmese pythons

• Did they have the virus when caught or was there exposure along the python-chain?

• Expanded testing to recently captured pythons from USGS, FWC, and Conservancy of Southwest Florida

• Didn’t find any pythons with ball python nidovirus• Many were positive for divergent nidovirus most closely

matching a Burmese python nidovirus found in a zoo

How Samples are Taken and Run

Initial Results

Virus Diversity

Burmese Python Nido Pos:Ball Python Nido Neg:

Ball Python Nido Pos:

Burmese Python Nido Neg:

Next Steps of the Project

• Screening native snake species• Getting larger viral genetic sequences to map out

virus diversity and distribution• Growing the virus in culture for In-vitro

experimentation

Acknowledgements & QuestionsDepartment of Comparative, Diagnostic, and Population Medicine at UF College of Veterinary Medicine & Department of Wildlife Ecology and Conservation at University of Florida, FWC, USGS, USDA APHIS, Conservancy of Southwest Florida, Colorado State University

Identifying prey